Electronic implants to bring paraplegics back on their feet

By Tereza Pultarova

Published Friday, May 16, 2014

A pan-European consortium is developing a revolutionary electronic device that will allow patients after severe spine injuries to walk again.

Part of the EU-funded NEUWalk project, the device, in principle a flexible microelectrode sensor, could be implanted into the spinal canal of a patient to bridge the disruption of the spinal cord by transferring electronic impulses across the damaged area.

“In the injured area, the nerve cells have been damaged to such an extent that they no longer receive usable information from the brain, so the stimulation needs to be delivered beneath that,” said Peter Detemple, from the Fraunhofer Institute for Chemical Technology in Mainz, Germany, coordinator of the NEUWalk project.

“The various electrodes of the array are located around the nerve roots responsible for locomotion. By delivering a series of pulses, we can trigger those nerve roots in the correct order to provoke a sequences of movements and support the motor function,” he said.

The team, consisting of experts from Germany, Switzerland, the UK, Italy, France and Finland, has already tested the device on rats, which had their spines previously partially or completely severed.

The rats went through a complex treatment including medication, rehabilitation and training, as well as implantation of the sensor. The researchers managed to restore the ability of the animals to use their hind limbs to the extent that they were able to run, climb the stairs and surmount obstacles.

“We were able to trigger specific movements by delivering certain sequences of pulses to the various electrodes implanted on the spinal cord,” Detemple said.

This summer, the researchers want to run the first trial with human patients. “We hope that we will be able to transfer the results of our animal testing to people,” Detemple said. “Of course, people who have suffered injuries to their spinal cord will still be limited when it comes to sport or walking long distances.”

The first two patients selected for the experiment are not completely paraplegic which means limited connection between the brain and legs still exists, making the whole situation far more simple. If the trial is successful, further experiments with a larger number of patients will follow.

The technique could also help patients with Parkinson’s disease in the future.

The project, awarded €9m from the EU’s Seventh Framework Programme for Research and Technological Development should be concluded this year.